General information
The instructions below guarantee a safe working environment and the safety of the electrical and electronic equipment of the vehicle. Additional instructions related to individual types of work are given in the relevant sections of the Manual.
Equipment
Before starting any diagnostic procedure, make sure that all equipment is working properly and that all cables and connectors are in good condition. Be sure to check the condition of the wires and lugs of the power supply circuit of the device.
Polarity
Connect the battery to the vehicle circuit correctly, and also observe the polarity when connecting diagnostic equipment.
High voltage circuits
When disconnecting a high voltage circuit, always use pliers with insulated handles and never allow the open end of the circuit to come into contact with other components, especially electronic control units.
Be careful when measuring the voltage at the ends of the ignition coil with the engine running. A high voltage pulse may occur on these contacts.
Connectors and wiring harnesses
The engine compartment is an environment that is particularly unfavorable for the placement of electrical system components and connectors:
- Before disconnecting or connecting diagnostic equipment, make sure that the surface of the electrical system components is dry and free from oil leakage.
- Detachable connectors must not show signs of oil, coolant or other liquids. Such damage can adversely affect the operation of systems or cause sudden failure.
- Never disassemble the electrical connectors by applying strong mechanical force, such as using a screwdriver as a lever or pulling on the harness.
- Before disassembling the connector, bring the connector lock to the disassembled position; before assembling the connector, make sure that the mutual position of the connector parts is correct.
- All protective elements (covers, cases) must be replaced if damaged.
In order to verify that a component is malfunctioning, follow the following sequence of actions:
- Switch off the ignition and disconnect the battery.
- Remove the component. Fix the disconnected wiring harness in a hanging position.
- When replacing a component, do not allow oily hands to touch the electrical connectors; insert the connector into the mating part until the latch is completely snapped into place.
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